Add xTickFormatter.
Add xTickFormatter.

notepad104/envisionjs,bigspotteddog/envisionjs,bigspotteddog/envisionjs,HumbleSoftware/envisionjs,HumbleSoftware/envisionjs,RobertoMalatesta/envisionjs,notepad104/envisionjs,RobertoMalatesta/envisionjs,notepad104/envisionjs,RobertoMalatesta/envisionjs